The effects of combined exposure to microplastics and contaminants are still not completely understood. To fill this gap, we assessed the effects of polyethylene terephthalate microplastic fibers (100 mg/L; 360 µm average length) on the toxicity of silver nanoparticles (AgNPs; 32 nm) and silver nitrate (AgNO₃; 0.1–10 µg Ag/L) to Daphnia magna. Acute immobilization (median effect concentration [EC50]) and cellular energy allocation (CEA; ratio between available energy and energy consumption) were determined in neonates (<24 h old) and juveniles (7 d old), respectively. The 48-h EC50 for AgNP and AgNO₃ (2.6 and 0.67 µg Ag/L, respectively) was not affected by the presence of microplastic fibers (2.2 and 0.85 µg Ag/L, respectively). No decrease in the available energy was observed: lipid, carbohydrate, and protein contents were unaffected. However, a significant increase in energy consumption was observed in animals exposed to AgNO₃ (250% compared with control) and to the combination of microplastic fibers with AgNP (170%) and AgNO₃ (260%). The exposure to microplastic fibers alone or in combination with both Ag forms decreased the CEA (values were 55–75% of control values). Our results show that after short-term exposure (48 h), microplastic fibers increased Ag toxicity at a subcellular level (i.e., CEA), but not at the individual level (i.e., immobilization). These results highlight the importance of combining different levels of biological organization to fully assess the ecotoxicological effects of plastics in association with environmental contaminants. Environ Toxicol Chem 2022;41:896–904. © 2021 SETAC

中文翻译：

---

微塑料纤维通过改变细胞能量分配增加了大型水蚤中 AgNP 和 AgNO3 的亚致死效应

仍不完全了解同时暴露于微塑料和污染物的影响。为了填补这一空白，我们评估了聚对苯二甲酸乙二醇酯微塑料纤维（100 mg/L；360 µm 平均长度）对银纳米颗粒（AgNPs；32 nm）和硝酸银（AgNO ₃；0.1–10 µg Ag/ L) 对大型蚤。分别在新生儿（<24 小时）和青少年（7 天）中测定急性固定（中值效应浓度 [EC50]）和细胞能量分配（CEA；可用能量与能量消耗之间的比率）。_{AgNP 和 AgNO 3}的 48 小时 EC50（分别为 2.6 和 0.67 µg Ag/L）不受微塑料纤维存在的影响（分别为 2.2 和 0.85 µg Ag/L）。没有观察到可用能量减少：脂质、碳水化合物和蛋白质含量不受影响。_{然而，在暴露于 AgNO 3}（与对照组相比为 250%）以及微塑料纤维与 AgNP（170%）和 AgNO ₃组合的动物中观察到能量消耗显着增加(260%)。单独暴露于微塑料纤维或与两种 Ag 形式结合使用会降低 CEA（值为对照值的 55-75%）。我们的研究结果表明，在短期暴露（48 小时）后，微塑料纤维在亚细胞水平（即 CEA）增加了 Ag 毒性，但在个体水平（即固定化）没有增加。这些结果强调了结合不同层次的生物组织以充分评估塑料与环境污染物相关的生态毒理学效应的重要性。环境毒物化学2022；41：896–904。© 2021 SETAC